Devices for driving toothed wheels



Aug. 19,- 1969 Filbd Jan. 19, 1968 DEVICE FOR DRIVING TOOTHED WHEELS F. DURAND 3,461,735

2 Sheets-Sheet 1 n1 vEA/v'ozi i9 Fro/2g 0/5 00" v @JAM f-(Mw Aug. 19, 1969 F. DURAND 3,461,735

DEVICE FOR DRIVING TOQTHED WHEELS Filed Jan. 19. 1968 2 Sheets-Sheet 2 y 1151/1 0 18-. F an ais Da a 7 wMm SM United States Patent o ABSTRACT OF THE DISCLOSURE An external gear and pinion drive has separate pinion support means retained in the tangential direction by a pivotal anchor rod. A roller mounted on the pinion support engages an internal surface of the gear for maintaining meshing engagement between the gear and the pinion.

The present invention relates in general to transmission devices of the type adapted to drive a toothed wheel or gear by means of a pinion, and has specific reference to devices of this character wherein the driving pinion is mounted in a support separate from the gear-carrying structure, this support being retained in the tangential direction by an anchor rod pivotally attached to a fixed point. On the other hand, adequate means are provided for maintaining the meshing engagement between the pinion and the driven gear.

Devices of this general character are advantageous in that they permit the movement of the pinion support so that the pinion has a relative freedom of movement in all directions which enables its teeth to engage with their entire surface the gear teeth, even if the gear has a defect such as buckling.

In known devices of this type various means have already been proposed for maintaining the proper meshing engagement between the pinion and the driven gear. These means may consist for example of rollers provided on the pinion support on either side of the plane comprising the axis of the driven gear and the axis of the driving pinion, these rollers being in constant rolling engagement with a track formed internally of the gear.

However, similar results may be obtained by providing means acting only in the plane comprising the gear axis and the pinion axis, but in this case the pinion support is allowed to pivot about the pinion axis. Therefore, some complementary means must be provided for limiting the amplitude of the possible oscillations of the pinion support about the pinion axis.

In view of the foregoing, it is the essential object of this invention to provide a driving device of the type set forth hereinabove which is designed for this specific purpose.

The driving device according to the present invention is characterised in that it comprises, in addition to the main anchor rod retaining the pinion support in the tangent direction, a complementary anchor rod having one end pivotally connected through the medium of a universal joint to the pinion support at a point located well outside the plane containing the axis of said pinion and a line interconnecting the fixed point of the main anchor rod to the middle point of the pinion axis, the opposite end of said complementary anchor rod being pivota-lly connected through the medium of another universal joint either to a fixed point or to said main anchor rod, at a point located in the vicinity of the above-defined plane, the distance between said second pivot point to said plane being inferior or equal to the distance from the first pivot point of said complementary anchor rod and said plane.

Under these conditions, the complementary anchor rod will efficiently and properly control or check the oscillation of the pinion support about the pinion axis.

3,461,735 Patented Aug. 19, 1969 ICE A few typical exemplary forms of embodiment of the device according to this invention will now be described with reference to the accompanying drawings, in which:

FIGURE 1 is a fragmentary diagrammatic side elevational view showing a first form of embodiment of the driving device of this invention;

FIGURE 2 is a horizontal section taken along the line lL-II of FIGURE 1;

FIGURE 3 is an elevational view of the same device as seen from the leftahand side of FIGURE 1;

FIGURE 4 is a vertical section taken along the line IVIV of FIGURE 1;

FIGURE 5 is a fragmentary sectional view similar to FIGURE 4 but showing on a larger scale a detail of a universal joint;

FIGURES 6 and 7 are side elevational views of two different forms of embodiment of the driving device of this invention;

FIGURE 8 is a fragmentary front elevational view showing another form of embodiment of the driving device, and

FIGURE 9 is a fragmentary partelevational, partsectional view of the device illustrated in FIGURE 8.

The transmission device illustrated in FIGURES 1 to 5 of the drawings is adapted to drive a toothed gear 1 provided with external teeth. To this end, the device comprises a driving pinion 2 mounted in a support or case 3 independent of the fixed frame structure supporting the gear 1, the shaft 23 of pinion 2 being trunnioned in the side walls of this support 3.

The proper meshing engagement between pinion 2 and gear 1 is ensured by means of a roller 4 carried by the pinion support 3 and kept in constant rolling engagement with a track 5 formed inside the gear 1, this track 5 being strictly concentric to the gear teeth.

Preferably, the shaft 26 carrying the roller 4 is mounted in a ball-and-sooket joint (not shown) carried by said support 3.

It may be noted that in the inoperative position of the driving device of this invention the axis of roller 4 lies in the plane II--I I containing the theoretical axis X--X of pinion 2 and the axis 0 of gear 1. Thus, the roller 4, whose function consists in maintaining the proper meshing engagement between the pinion 2 and gear 1, is effective only in this plane, so that the possibility subsists that the pinion support 3 oscillates or tilts about the pinion axis.

However, this support 3 is retained in the tangential direction by an anchor rod 7 having one end pivotal'ly connected to a fixed point 6 and the opposite end pivotally connected at 8 to the pinion support 3.

It may also be emphasized that this anchor rod 7, when inoperative, lies in the median plane YY of the pinion teeth, which is therefore perpendicular to the pinion axis. On the other hand, when this anchor rod is inoperative its axis, which extends radially from the pinion centre, is parallel to a tangent to the gear which passes through the point of contact between the gear teeth and the driving pinion.

The two joints or pivotal connections 6 and 8 provided at the ends of the anchor rod 7 are of the universal type permitting swivelling movements in all directions. To this end, these joints may consist of ball-and-so'cket devices.

A typical example of a joint of this character is illustrated in FIGURE 5, this pivotal connection being provided between the anchor rod 7 and a fixed point, and consisting of a ball 6 disposed in a corresponding partspherical recess of a socket 16 carried by the relevant end of anchor rod 7. This ball 6 is carried by a stud 17 secured by a nut to a lug 18 secured in turn to the floor or to a fixed frame structure 19 of the installation.

Since the two joints6 and 8 consist of universal joints the pinion support 3 can swivel as necessary in the space so that the pinion teeth may properly engage with their entire surface the gear teeth, even if the gear has defects such as buckling or the like.

However, according to an essential feature of the driving device of this invention this device comprises a complementary anchor rod 9, in addition to the aforesaid anchor rod 7. Like the main anchor rod 7, this complementary anchor rod 9 lies substantially in the median plane YY of the pinion teeth which is therefore perpendicular to the pinion axis 0.

One end of this complementary anchor rod 9 is pivotally connected to the pinion support 3 at a point located well outside the plane containing the axis XX of this pinion and a line connecting the fixed point 6 of the pivotal connection between the main anchor rod 7 and the point M located on said axis XX in the median plane of the pinion. Therefore, this point M corresponds to the intersection of axis XX with plane YY (see FIGURE 3).

On the other hand, in the example illustrated in FIG- URES 1 to 4, the plane thus defined merges with plane YY. However, these twoplanes may also be separate from each other as in the example shown in FIGURES 8 and 9.

The opposite end of the complementary anchor rod 9 is pivot-ally connected to the main anchor rod 7 at a point 11 located in the vicinity of the above-defined plane.

Actually, the first pivotal connection 10 is disposed on an extension of the pinion support 3 which has the same direction as the main anchor rod 7.

As will be clearly seen in FIGURE 1 the complementary anchor rod 9 will thus form an angle of about 90 degrees in relation to the main anchor rod 7. However, this angle might have a different value. Due to the specific arrangement of its pivot points the complementary anchor rod 9 will somewhat control or check the pivotal movements of the pin-ion support 3 about the pinion axis XX.

In fact, since the roller 4, whose function as already explained hereinabove consists in keeping the pinion in proper meshing engagement with the gear teeth, is operative only in the plane IIII formed by the pinion axis XX with the gear axis 0, the support 3 could if desired pivot freely in relation to the pinion axis XX, if no complementary anchor rod 9 has been contemplated.

In this respect it may be noted that the complementary anchor rod 9 constitutes with the main anchor rod 7 a kind of triangular assembly safely precluding any possibility of untimely or undesired tilting of the pinion support 3.

FIGURE 6 illustrates another possible form of embodiment of the driving device of this invention, which diifers from the preceding one only in that the roller 4 provided for maintaining the proper meshing engagement between the driving pinion and the driven gear is dispensed with. In fact, in this alternate form of embodiment this proper meshing engagement is ensured by providing a reaction ro'd 4a having its longitudinal axis disposed in the plane containing the axes of pinion 3 and gear 1. Besides, this reaction ro'd 4a lies in a plane disposed in the middle of the pinion teeth and therefore perpendicular to the pinion axis XX.

Finally, the pivotal connections 21 and 22 at the ends of this reaction rod, which lies respectively on the pinion support and on a fixed point, consist of universal joints permitting swivelling movements in all directions. Thus, ball-and-socket joints may be used to constitute these pivota l connections.

Under these conditions, this reaction rod 4a is elfective only in the plane containing the axis XX of the pinion and the axis of the toothed gear, like the roller 4 provided in the preceding form of embodiment.

However, in this alternate form of embodiment as in the preceding one the complementary anchor rod 9 is pr vided 'for controlling or checking the possible tilting of the pinion support 3 about the pinion axis XX.

FIGURE 7 illustrates another form of embodiment wherein the proper meshing engagement between the gear and pinion is maintained by a roller 4 as in the case illustrated in FIGURE 1.

However, in the arrangement shown in FIGURE 7 the complementary anchor ro'd 9a is not disposed as in the preceding examples.

In FIGURE 7, one end of this complementary anchor rod 9a is still pivotally connected to the pinion support 3 at a point 10a located outside the plane containing the pinion axis and the line interconnecting the fixed pivot point 6 of the main anchor rod 7 and the pinion axis XX. However, the opposite end of this complementary rod 9a, instead of being pivoted to the main anchor rod 7 as in the preceding case is attached to a fixed pivot point 11a located in the vicinity of the fixed pivot point 6 of the main anchor rod 7.

This fixed pivot point 11a must be as close as possible to the above-defined plane containing the pinion axis and the line interconnecting the fixed pivot point 6 of the main anchor rod 7 and the pinion axis XX. In fact, its distance from this plane should not exceed the distance measured from pivot point 10a to the same plane. This is actually the case in the example illustrated in FIGURE 7, wherein the two anchor rods 7 and 9a are substantially parallel.

With this arrangement, as in the preceding one, the possibility of controlling or checking the tilting of the pinion support 3 about the pinion axis XX is preserved. In fact, this control action is provided for by the complementary anchor rod 9a.

FIGURES 8 and 9 illustrate a driving device similar to the one shown in FIGURE 1. However, in this alternate form of embodiment the roller 4 holding the driving pinion 2 in proper meshing engagement with the gear 1 is replaced by a pair of rollers 4b disposed on either side of the plane containing the pinion axis XX and the gear axis (not shown), these rollers 4b being in constant rolling contact with a track 5b formed internally of gear 1.

The rollers 4b are mounted on shafts carried by a rocker 12 'fulcrumed on a pivot pin 13 carried in turn by the pinion support 3b.

The pinion 2 is driven through a primary reducing gear of which the toothed wheel 15 is keyed on the shaft 23 of driving pinion 2.

Furthermore, one end of the shaft 24 of the worm 14 meshing with said toothed wheel 15 projects from the support 3b which can be operatively connected to any driving or power 'sha-tt.

On the other hand, as already stated, the general arrangement of this transmission device is similar to that of the device illustrated in FIGURE 1.

In fact, the pinion support 3b is retained in the tangential direction by the main anchor rod 7b pivoted at 8b to this support and at 6b to a fixed pivot point.

Besides, this device comprises 'a complementary anchor rod 912 having one end pivotally connected at 10b to an extension 20b of support 3b and the other end pivotally connected at 11b to the main anchor rod 7b, as shown.

As in the preceding case, the function of this complementary anchor rod is to control or check the possible tilting of the pinion support 3b about the pinion axis XX.

What I claim is:

1. Device for dividing a toothed gear, comprising in combination at least one pinion for driving said gear; a movable support for said pinion; an anchor rod retaining said movable support in the tangent direction of said gear, said anchor rod being pivotally connected at one end to said support and at the opposite end to a fixed pivot point; universal joints for these connections; means adapted to maintain the proper meshing engagement between said pinion and said gear, said means being capable of retaining said support only in the plane containing the pinion axis and the gear axis, whereby said pinion support may pivot, if necessary, about the pinion axis; a complementary anchor rod having one end pivotally connected by means of a universal joint to said pinion support at a point thereof located Well outside the plane containing the pinion axis and the line interconnecting said fixed pivot point of said main anchor rod and the middle point of the pinion axis, the opposite end of said complementary anchor rod being pivotally connected through another universal joint to a point located in the vicinity of the above-defined plane, the distance from said second pivot point to said plane being at the most equal to the distance between said first pivot point of said complementary anchor rod and said plane.

2. A driving device according to claim 1, in which said second pivot point whereat said complementary anchor rod is pivoted lies on said man anchor rod retaining the pinion support in the tangential direction, said main and complementary anchor rods forming together an angle of about 90 degrees, said first pivot point of said complementary anchor rod lying on an extension of said pinion support which has the same direction as said main anchor rod.

3. A driving device according to claim 1, in which said second pivot point of said complementary anchor rod is fixed and is located in the vicinity of the fixed pivot point of said main anchor rod.

References Cited UNITED STATES PATENTS LEONARD H. GERIN, Primary Examiner 

